diff --git a/src/config.ts b/src/config.ts
index c92f872..a6b45c3 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -118,19 +118,43 @@ export class CacheConfig {
     let lockHash = core.getState(STATE_LOCKFILE_HASH);
     let keyFiles: Array<string> = JSON.parse(core.getState(STATE_LOCKFILES) || "[]");
 
+    // Constructs the workspace config and paths to restore:
+    // The workspaces are given using a `$workspace -> $target` syntax.
+
+    const workspaces: Array<Workspace> = [];
+    const workspacesInput = core.getInput("workspaces") || ".";
+    for (const workspace of workspacesInput.trim().split("\n")) {
+      let [root, target = "target"] = workspace.split("->").map((s) => s.trim());
+      root = path.resolve(root);
+      target = path.join(root, target);
+      workspaces.push(new Workspace(root, target));
+    }
+    self.workspaces = workspaces;
+
     if (!lockHash) {
-      const globber = await glob.create("**/Cargo.toml\n**/Cargo.lock\nrust-toolchain\nrust-toolchain.toml", {
-        followSymbolicLinks: false,
-      });
-      keyFiles = await globber.glob();
+      hasher = crypto.createHash("sha1");
+
+      async function globHash(pattern: string): Promise<string[]> {
+        const globber = await glob.create(pattern, {
+          followSymbolicLinks: false,
+        });
+        return await globber.glob();
+      }
+
+      keyFiles = keyFiles.concat(await globHash("rust-toolchain\nrust-toolchain.toml"));
+      for (const workspace of workspaces) {
+        const root = workspace.root;
+        keyFiles = keyFiles.concat(await globHash(`${root}/**/Cargo.toml\n${root}/**/Cargo.lock\n${root}/**/rust-toolchain\n${root}/**/rust-toolchain.toml`));
+      }
+
       keyFiles.sort((a, b) => a.localeCompare(b));
 
-      hasher = crypto.createHash("sha1");
       for (const file of keyFiles) {
         for await (const chunk of fs.createReadStream(file)) {
           hasher.update(chunk);
         }
       }
+
       lockHash = hasher.digest("hex");
 
       core.saveState(STATE_LOCKFILE_HASH, lockHash);
@@ -138,22 +162,10 @@ export class CacheConfig {
     }
 
     self.keyFiles = keyFiles;
+
     key += `-${lockHash}`;
     self.cacheKey = key;
 
-    // Constructs the workspace config and paths to restore:
-    // The workspaces are given using a `$workspace -> $target` syntax.
-
-    const workspaces: Array<Workspace> = [];
-    const workspacesInput = core.getInput("workspaces") || ".";
-    for (const workspace of workspacesInput.trim().split("\n")) {
-      let [root, target = "target"] = workspace.split("->").map((s) => s.trim());
-      root = path.resolve(root);
-      target = path.join(root, target);
-      workspaces.push(new Workspace(root, target));
-    }
-    self.workspaces = workspaces;
-
     self.cachePaths = [CARGO_HOME];
     const cacheTargets = core.getInput("cache-targets").toLowerCase();
     if (cacheTargets === "true") {